1. Field
The present application relates to a signal processing apparatus and an imaging apparatus which reduce a noise signal included in a sound signal.
2. Description of the Related Art
As a method of reducing a component based on a noise sound (noise component) from a sound signal in which a sound of target and a noise sound are mixed, it is generally performed to estimate the noise sound from the obtained sound signal and to subtract a signal of the estimated noise sound (referred to hereinafter as noise signal) from the sound signal (Japanese Unexamined Patent Application Publication No. 2005-195955).
With the use of such a method, when the noise sound is previously obtained or the noise sound is formed of a periodical sound, an intensity of the noise sound and a timing at which the noise sound is included can be easily estimated, so that the noise signal can be appropriately reduced from the sound signal. However, if a sound generated when driven various mechanisms and the like inside an apparatus (referred to hereinafter as operation sound) is recognized as the noise sound, since a timing at which the aforementioned operation sound is generated is aperiodic, it is difficult to estimate the noise sound included in the sound signal. For this reason, a noise component called musical noise may be included in a sound signal after the noise signal is subtracted therefrom.